Number trick with 1089
The number trick with 1089 has been around for centuries. To impress someone with this trick, he or she will need paper and pencils:
Here is how it goes:
Step #1:
Have the person write down any three digits number with
decreasing digits (432 or 875).
Step #2:
Reverse the number you wrote in step #1.
Step #3:
Subtract the number obtained in step #2 from the number you wrote in step #1
Step #4:
Reverse the number obtained in step #3
Step #5:
Add the numbers found in step #3 and step #4
Example #1:
Step #1:
Have the person write down any three digits number with decreasing digits: 752
Step #2:
Reverse the number you wrote in step #1: 257
Step #3:
Subtract the number obtained in step #2 from the number you wrote in step #1: 752  257 = 495
Step #4:
Reverse the number obtained in step #3: 594
Step #5:
Add the numbers found in step #3 and step #4: 495 + 594 = 1089
Example #2:
Step #1:
Have the person write down any three digits number with decreasing digits: 983
Step #2:
Reverse the number you wrote in step #1: 389
Step #3:
Subtract the number obtained in step #2 from the number you wrote in step #1: 983  389 = 594
Step #4:
Reverse the number obtained in step #3: 495
Step #5:
Add the numbers found in step #3 and step #4: 594 + 495 = 1089
Example #3:
Step #1:
Have the person write down any three digits number with decreasing digits: 210
Step #2:
Reverse the number you wrote in step #1: 012
Step #3:
Subtract the number obtained in step #2 from the number you wrote in step #1: 210  012 = 198
Step #4:
Reverse the number obtained in step #3: 891
Step #5:
Add the numbers found in step #3 and step #4: 198 + 891 = 1089
This number trick with 1089 works with any 3 digits number as long as you choose a number with decreasing digits in step #1
So, it does not matter what number the person choose in step #1, have the person do the math and pretend you are not looking. When you call
the answer as 1089, the person will be shocked! Cool!

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